Characterizing Wildland Firefighters’ Thermal Environment During Live-Fire Suppression

Wildland firefighters work under adverse environments (e.g., heat and fire exposure), which contribute to increasing the heat strain. Despite this there is a paucity of knowledge about the thermal environment in real wildfire suppression scenarios. Therefore, the main purpose of this study was to characterize the environmental thermal exposure and the risk of heat burn injuries during real wildfire suppression (n = 23). To characterize the wildland firefighter’s (n = 5) local thermal exposure, measurements of air temperature and heat flux were performed. Heat flux measurements were made using four thin-planar heat flux sensors. Two were affixed on the outer surface of the garment on the left chest and thigh. Two other sensors were placed on the inner surface of the fabric in parallel to those placed externally. Four thermal classes were defined based on the heat flux across the inner sensors (≤1000, ≤5000, ≤7000, and >7000 W·m−2). The risk of pain and first-degree burns were calculated using the dose of thermal radiation method. The inner sensors mean and maximum heat flux and environment temperature were 286.7 ± 255.0 and 2370.4 ± 3004.5 W·m−2 and 32.6 ± 8.9 and 78.0 ± 8.9◦C, respectively. Approximately 81, 15, and 3.5% of the exposure time the heat flux was ≤1000, >1000–5000, and >5000 W·m−2, respectively. The highest average and maximum thermal dose values were ∼94 and ∼110 (kW·m−2)4/3·s. In conclusion, the thermal exposure obtained may be considered light. However, high thermal exposure values may be obtained in punctual moments, which can elicit first-degree burns.SIThis study was financially support from the Ministerio de Economía, Industria y Competitividad (Spain) grant (DEP2016-79762-P AEI/FEDER, UE) and has been funded by the Empresa de Transformación Agraria, S.A. (TRAGSA

Impact of Different Personal Protective Clothing on Wildland Firefighters' Physiological Strain

Wildfire firefighting is an extremely demanding occupation performed under hot environment. The use of personal protective clothing (PPC) is needed to protect subjects from the thermal exposure. However, the additional use of PPC may increase the wildland firefighters’ physiological strain, and consequently limit their performance. The aim of this study was to analyze the effect of four different PPC on the physiological strain of wildland firefighters under moderate conditions (30◦C and 30% RH). Eight active and healthy wildland firefighters performed a submaximal walking test wearing a traditional short sports gear and 4 different PPC. The materials combination (viscose, Nomex, Kevlar, P-140 and fire resistant cotton) used during the PPC manufacturing process was different. During all tests, to simulate a real scenario subjects wore a backpack pump (20 kg). Heart rate, respiratory gas exchange, gastrointestinal temperature, blood lactate concentration, perceived exertion and temperature and humidity underneath the PPC were recorded throughout tests. Additionally, parameters of heat balance were estimated. Wearing a PPC did not cause a significant increase in the subjects’ physiological response. The gastrointestinal temperature increment, the relative humidity of the microclimate underneath the PPC, the sweat residue in PPC, the sweat efficiency, the dry heat exchange and the total clothing insulation were significantly affected according to the PPC fabric composition. These results suggest that the PPC composition affect the moisture management. This might be taken into account to increase the wildland firefighters’ protection in real situations, when they have to work close to the flames.SIFinancial support from Ministerio de Economía, Industria y Competitividad (Spain) grant (DEP2016-79762-P). In addition, the study has been funded by Empresa de Transformación Agraria, S.A. (TRAGSA)

BIOMECHANICAL ASSESSMENT OF AERODYNAMIC RESISTANCE IN PROFFESSSIONAL CYCLISTS: METHODOLOGICAL ASPECTS

The aim of this study was to measure and compare the aerodynamic resistance (RA) in five different professional road cyclists obtained from a wind tunnel and to establish modification that into a performance improvement. Five professional cyclists from the Kelme-Costa Blanca Team were studied in five positions, four on the aerobike and one on the standard bike. From our results we conclude that establishing small modifications in the aerohandlebars, which result in a more profitable position, can reduce RA. The use of aerohelmet was not shown to be always useful. It is necessary to take into account the technique employed, corrected RA values with the anthropometric characteristics, static vs dynamic assessment when comparing professional cyclists RA

Estudio del apoyo metatarsal en bipedestación mediante podoscopio electrónico de alta resolución.

Con el jin de estudiar el apoyo metatarsal en bipedestación se han realizado 780 registros en la plataforma PDS 93, correspondientes a 390 individuos, no seleccionados, sin patología de la marcha, 234 varones y 156 mujeres, con edades comprendidas entre 24 y 41 años (edad media de 29,9 años). En cada registro se ha recogido la presión ejercida por cada metatarsiano, relacionando la carga obtenida con el peso, conjiguración mecánica del pie y huella plantar: Los resultados obtenidos se han procesado estadísticamente por medio del programa SPSS. El porcentaje de las cargas medias obtenidas para cada metatarsiano han sido: 16,85, 21,25, 23,88, 20,24 y 17,78%, existiendo dqerencias sign$cativas para el apoyo de los metatarsianos centrales (p < 0,001). Todos los metatarsianos soportan carga en bipedestación, de acuerdo con las teorías actuales. Sin embargo, aunque la distribución del peso para el primer metatarsiano se aproxima al doble de los otros, la carga máxima en g/cm2 se realiza en los metatarsianos centrales

Fractional Contribution of Wildland Firefighters’ Personal Protective Equipment on Physiological Strain

[EN] Activities performed by wildland firefighters are carried out wearing a personal protective equipment (PPE). Although the PPE protects workers from a wide variety of hazards, it may increase their physiological response and limit their performance. The aim of this study was to analyze the effect of the protective clothing (PPC) and the rest of the PPE elements (i.e., helmet, neck shroud, gloves, goggles, and mid-calf leather boots) on the wildland firefighters’ thermophysiological response during a moderate- intense exercise. Six male wildland firefighters performed, in a counterbalanced order, a 120 min graded exercise test wearing three different clothing configurations: (i) a traditional short sports gear (SG), (ii) a PPC, and (iii) a complete firefighters’ PPE. Trials were conducted on separate days at the same time of the day (12:00–15:00 h) and under climate-controlled conditions (∼30◦C and ∼30% relative humidity). Heart rate, respiratory gas exchange, gastrointestinal and skin temperature, blood lactate concentration were recorded throughout the tests. Additionally, parameters of heat balance were estimated. Exercise time was shorter (p < 0.001) wearing the PPE (62.4 ± 13.3 min) than with the PPC (115.5 ± 5.0 min) and SG (118.2 ± 20.7 min). The increment of gastrointestinal temperature with the PPE (1.8 ± 0.3◦C) was greater (p < 0.05) than the observed in PPC (1.2 ± 0.6◦C) and SG (1.0 ± 0.2◦C). The use of PPC increased (p < 0.05) subjects’ metabolic demand and skin temperature versus SG during the last 20 min of the test. The sweat retention in the PPE (1,045.7 ± 214.7 g) and PPC (978.3 ± 330.6 g) was significantly higher than that obtained in the SG (510.0 ± 210.0 g). Sweat efficiency decreased (p < 0.05) in the following order: PPE (45.6 ± 18.3%), PPC (64.3 ± 7.8%), and SG (79.3 ± 7.0%). These results highlight the importance of the PPE elements in the subjects’ thermal strain. The reduction in the sweat evaporation produced by the PPE, together with the ensemble mass caused a substantial increase in the subjects’ thermophysiological response. As a consequence the performance was reduced by ∼50%.S

"Fat but powerful'' paradox: association of muscle power and adiposity markers with all-cause mortality in older adults from the EXERNET multicentre study

Objectives: To assess the influence of muscle power and adiposity on all-cause mortality risk and to evaluate the fat but powerful'' (F+P) (or fat but fit'') paradox in older adults. Methods: A total of 2563 older adults (65 €''91 years old) from the EXERNET multicentre study were included. Adiposity (body mass index (BMI), waist circumference, body fat percentage (BF%) and fat index), allometric and relative power (sit-to-stand muscle power test) and various covariates (age, sex, hypertension, smoking status and walking and sitting times per day) were registered at baseline. All-cause mortality was recorded during a median follow-up of 8.9 years. Participants were classified into four groups: lean and powerful (L+P), F+P, lean but weak and fat and weak (F+W). Cox proportional hazard regression models and adjusted HRs were calculated. Results: According to BMI and waist circumference, all-cause mortality risk was reduced in the F+P (HR=0.55 and 0.63, p=0.044 and 0.049, respectively) and L+P (HR=0.57 and 0.58, p=0.043 and 0.025, respectively) groups. According to BF%, all-cause mortality decreased in the L+P group (HR=0.53; p=0.021), and a trend for a reduction was reported in the F+P group (HR=0.57; p=0.060). According to fat index, a survival benefit was only noted in the L+P group (HR=0.50; p=0.049). Higher levels of relative power reduced all-cause mortality risk among older people (HR=0.63 and 0.53, p=0.006 and 0.011, respectively). Conclusion: Powerful older people exhibited a reduced 9-year all-cause mortality regardless of BMI, waist circumference and BF%. Obesity according to fat index blunted the survival benefits of being powerful

Molecular Plasmonic Silver Forests for the Photocatalytic-Driven Sensing Platforms

Structural electronics, as well as flexible and wearable devices are applications that are possible by merging polymers with metal nanoparticles. However, using conventional technologies, it is challenging to fabricate plasmonic structures that remain flexible. We developed three-dimensional (3D) plasmonic nanostructures/polymer sensors via single-step laser processing and further functionalization with 4-nitrobenzenethiol (4-NBT) as a molecular probe. These sensors allow ultrasensitive detection with surface-enhanced Raman spectroscopy (SERS). We tracked the 4-NBT plasmonic enhancement and changes in its vibrational spectrum under the chemical environment perturbations. As a model system, we investigated the sensor’s performance when exposed to prostate cancer cells’ media over 7 days showing the possibility of identifying the cell death reflected in the environment through the effects on the 4-NBT probe. Thus, the fabricated sensor could have an impact on the monitoring of the cancer treatment process. Moreover, the laser-driven nanoparticles/polymer intermixing resulted in a free-form electrically conductive composite that withstands over 1000 bending cycles without losing electrical properties. Our results bridge the gap between plasmonic sensing with SERS and flexible electronics in a scalable, energy-efficient, inexpensive, and environmentally friendly way.</p

Harmonization Process and Reliability Assessment of Anthropometric Measurements in the Elderly EXERNET Multi-Centre Study

Background: The elderly EXERNET multi-centre study aims to collect normative anthropometric data for old functionally independent adults living in Spain.Purpose: To describe the standardization process and reliability of the anthropometric measurements carried out in the pilot study and during the final workshop, examining both intra- and inter-rater errors for measurements.Materials and Methods: A total of 98 elderly from five different regions participated in the intra-rater error assessment, and 10 different seniors living in the city of Toledo (Spain) participated in the inter-rater assessment. We examined both intra- and inter-rater errors for heights and circumferences.Results: For height, intra-rater technical errors of measurement (TEMs) were smaller than 0.25 cm. For circumferences and knee height, TEMs were smaller than 1 cm, except for waist circumference in the city of Ca´ceres. Reliability for heights and circumferences was greater than 98% in all cases. Inter-rater TEMs were 0.61 cm for height, 0.75 cm for knee-height and ranged between 2.70 and 3.09 cm for the circumferences measured. Inter-rater reliabilities for anthropometric measurements were always higher than 90%.Conclusion: The harmonization process, including the workshop and pilot study, guarantee the quality of the anthropometric measurements in the elderly EXERNET multi-centre study. High reliability and low TEM may be expected when assessing anthropometry in elderly population.SIThe elderly EXERNET multi-centre study has been supported by the Ministerio de Trabajo y Asuntos Sociales (104/07), Universidad de Zaragoza (UZ 2008-BIO-01) and Ministerio de Sanidad, Servicios Sociales e Igualdad (147/2011). A. Go´ mez-Cabello has received a PhD grant from the Gobierno de Aragon (B059/ 09). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

DERIVE and Linear Algebra

This work describes an experience with a methodology for learning based on competences in Linear Algebra for engineering students. The experience has been based in autonomous team work of students. DERIVE tutorials for Linear Algebra topics are provided to the students. They have to work with the tutorials as their homework. After, worksheets with exercises have been prepared to be solved by the students organized in teams, using DERIVE function previously defined in the tutorials. The students send to the instructor the solution of the proposed exercises and they fill a survey with their impressions about the following items: ease of use of the files, usefulness of the tutorials for understanding the mathematical topics and the time spent in the experience. As a final work, we have designed an activity directed to the interested students. They have to prepare a project, related with a real problem in Science and Engineering. The students are free to choose the topic and to develop it but they have to use DERIVE in the solution. Obviously they are guided by the instructor. Some examples of activities related with Orthogonal Transformations will be presented